Shock absorber for railway car trucks



' 0t.23, 1951 AEDENTLER 2,572,453

SHOCK ABSORBER FOR RAILWAY CAR TRUCKS Filed NOV. 25, 1949 Patented Oct. 23, 1951 SHOCK ABsoRBER FoR RAILWAY Y CAR TRUCKS Arnold E. Daentler, La Grange, Ill., assignor to W. H. Miner, Inc., Chicago,v Ill., a corporation of Delaware ,y

Application November 2s, 1949, seria1No.1z9,o31

3 Claims.'v l

This invention relates to improvements in friction shock absorbers for snubbing or dampening the action of railway car truck springs.

One object of the invention is to provide a shock absorber, including ar friction casing, friction shoes slidingly telescoped within the casing in frictional contact with the interior walls thereof, and spring means opposing movement of the shoes inwardly of the casing and for spreading the shoes apart. f

A more specific object of the invention is to provide a mechanism of the character described in the preceding paragraph, wherein the spring means is in the form of a volute spring member which opposes inward movement of the shoes and spreads the same apart against the interior walls of the casing into tight frictional engagement therewith.

Other objects of the invention will more clearly appear from the description and claims hereinafter following.

In the accompanying drawing forming a part of this specification, Figure 1 is a top plan view of my improved friction shock absorber. Figure 2 is a transverse, vertical sectional view, corresponding substantially to the line 2-2 of Figure l. Figure 3 is a horizontal sectional View, corresponding substantially to the line 3-3 of Figure 2.

As shown in the drawing, my improved shock absorber comprises broadly a friction casing A, three friction shoes B-B-B, and a volute spring C.

The casing A is in the form of a substantially cylindrical, tubular member, open at its top end and closed at its bottom end by a transverse wall I0. The interior of the casing presents 'longitudinally extending, transversely curved friction surfaces I I-I I-I I, which terminate short of the bottom end of the casing. The interior friction surface portion of the casing is provided with three relatively short, lengthwise disposed, guide slots I2-I2-I2, which extend upwardly from the lower ends of the friction surfaces and terminate in transverse stop shoulders I 3-I3--I3 at their upper ends. The guide slots are spaced 120 degrees apart, the individual slots being disposed substantially centrally of the friction surfaces of the casing. The bottom wall I of the casing is provided with an upstanding, central boss I4, which is hollow and forms a seat adapted to accommodate the usual spring centering lug of the bottom spring plate of a truck spring cluster.

The friction shoes B are three in number and are telescoped within the open end of the casing,

the same being arranged symmetrically about the central longitudinal axis of said casing. Each shoe B comprises an elongated, transversely curved, platelike section l5, having a transversely curved friction surface IE on its outer side, slidingly engaged with one of the friction surfaces I I of the casing. At the upper end, each shoe has a laterally inwardly extending fiange IIforming an abutment for the volute spring C. Each shoe also has a laterally outwardly projecting, arcuate flange I8 at its upper end, in transverse align- Vment with the flange I1. The anges I8-I8-I8 of the shoes form stop members adapted to engage the outer end of the casing to limit inward movement of the shoes. At its lower end, each shoe has a laterally outwardly projecting, central stop lug I9 guided in the corresponding slot I2 of the casing and engageable with the stop shoulder I3 of said slot to limit outward or upward movement of the shoe. The inner ends of the flanges I'I-Il-I'l of the three shoes are cut out, as clearly shown in Figures 1 and 2, to provide a seat 20, which is adapted to accommodate the usual spring centering projection of the top spring plate of the truck spring cluster.

The volute spring C is in the form of a band of metal, coiled to volute formation. The spring C, which is of larger diameter at its upper end than at its lower end, is arranged between the shoes B-B--B, with its end of larger diameter abutting the underneath sides of the flanges I'I-I'I- I'I of the shoes B-B-B, and its lower end, which is of smaller diameter, seated on top of the boss I4 of the bottom wall Il! of the casing. In forming the volute spring C, it is coiled rather loosely, so that it is radially compressed between the shoes when the latter are in assembled relation within the casing A. The spring C, thus being under initial radial compression, holds the shoes in tight frictional contact with the friction surfaces of the casing.

My improved shock absorber preferably replaces one or more of the spring units of a truck spring cluster of a railway car, being interposed between the top and bottom spring plates of said cluster.

The operation of my improved shock absorber is as follows: Upon the spring cluster of the truck of a railway car being compressed between the spring follower plates of the cluster, the shoes B-B-B are forced downwardly with respect to the casing A, thereby sliding the shoes along the friction surfaces of the casing and compressing the volute spring C in lengthwise direction. During this compression lengthwise of the volute spring C, due to its being confined between the shoes, the turns of the same are pressed against each other into tight frictional engagement, while being compressed lengthwise, and the shoes are held in tight frictional contact with the friction surfaces of the casing. High frictional resistance is thus provided to snub the action of the truck springs. Compression of the shock absorber is positively limited by engagement of the flanges |8-I8-I8 of the shoes with the upper end of' the casing A.

Upon recoil of the truck springs, the actuatngY force on the upper end of the shoes is reduced, permitting restoration of the. shoes to the ful-l release position shown in YFigure 2, through lengthwise expansion of the volute spring C.

I claim:

1. In a friction shock absorber, the combination with a friction casing open at one end `and closed at the other end; of friction shoes slidingly tel'escoped within the open end of the casing; laterally inwardly projecting anges on the outer ends of said shoes;v and a lengthwise` extending volute spring bearing at opposite ends on said anges of the shoes and the closed end of theeasing.

2. a friction shockl absorber, the combination with a friction casing open at one end and closedat the other end; of friction shoes slidinglyv telescoped Within the open end of the casing; laterally inwardly projecting flanges on the outer ends of said shoes; and a lengthwise extending volute spring bearing at opposite ends on said anges of the shoes and the closed end of the casing, said volute spring being under radial compression between said shoes.

3. In a friction shock absorber, the combination with a friction casing closed at its bottom endA and open at its top end; of a plurality of friction shoes slidingly telescoped within the open end of said casing, said shoes having laterally inwardlyproiecting nanges at their upper ends; anda volute spring within said casing embraced by said shoes and under radial compression between the same, said volute spring having its Aupper end abutting said flanges of the shoes and its lower'end supported against said closed end v of the`4 casing saidyolute spring being of greater diameter at its upper than at its lower end.

" ARNOLD E. DENTLER.

Y REFERENCES CITED- The Yfollowing.; references are of record in the le of this patent:

UNITED STATES PATENTS 

